“Compact, workable Apex Pro with subtle distance help. A rung-2 set for the strong ballstriker who still wants a touch of speed.”

The Apex Pro 21 replaced the cavity-back construction of its predecessors with a forged hollow body -- the first Apex iron built that way -- to fit up to 90 grams of tungsten into a single head, more than any previous Apex model. Callaway called that mass placement the Tungsten Energy Core, paired with the brand's Flash Face technology in a forged iron for the first time, aimed at high COR and consistent ball speed even on off-center hits. Despite the added engineering, the head reads as understated at address: a long, narrow sole, thin top line and only a touch of offset, positioned as the scratch-to-single-digit option in Callaway's three-way 2021 forged split alongside the standard Apex 21 and Apex MB 21.

Very well reviewed on release (near-5/5 average scores across Callaway Pre-Owned, Global Golf and PGA Tour Superstore) but reviewed as a strong iteration on a known formula, not a landmark -- no lasting collector or forum mythology has formed around it, and it was one of three siblings released the same year rather than a standalone story.

Scratch and single-digit players who want tour-level looks and workability with a genuine forgiveness cushion built in via the hollow body -- a strong 'best of both' pick for a strong ball-striker who occasionally mis-hits under pressure. A true beginner or high-handicapper is still better served by the Apex 21 or Apex DCB 21.

• First Apex iron built with hollow-body construction instead of a cavity-back.
• Uses up to 90 grams of tungsten per iron -- the most tungsten ever fit into an Apex iron at the time.
• First forged Apex iron to use Callaway's Flash Face technology, previously seen mainly in cast game-improvement irons.
• Carried customer ratings around 4.7-4.8 out of 5 across major pre-owned and tour-shop retailers shortly after release.
• Sold as a 3-PW set at an MSRP of $1,499, the highest price point in the 2021 Apex family.

Part of Callaway's 2021 three-tier forged Apex family, competing with Titleist's T100/T150 and Mizuno's Pro 221/223 in the better-player hollow/forged category. It was the first Apex to use hollow-body construction, a design path Callaway continued refining in the Apex CB/Pro lines that followed.

Retailed at $1,499 in 2021. 2nd Swing listings currently span roughly $280-$880 depending on shaft and condition, which reflects graded/reconditioned retail pricing; realistic 2026 private-party value for a clean steel set is lower, roughly $400-$600.