Tern Pinhead Seatpost Lockset GSD Gen 1/HSD Ebike 305 × 185 mm) is

305 × 185 mm) is for passengers 140 cm and over — approximately age 10 and up

Tern's own KLICKfix-compatible accessories include the Hold 'Em Basket Gen 1

It mounts securely but comes off easily

it's not an in-use adjustment

Tern Pinhead Seatpost Lockset GSD Gen 1/HSD Ebike 305 × 185 mm) isThe Pinhead seatpost locks for GSD & HSD prevent the removal of your seatposts. Once installed, the seatpost locks remain permanently on your bicycle, even when you ride. When you need to adjust your saddle height, your Pinhead tool lets you do this quickly and easily with a 15mm wrench. Pinhead locks cannot be removed with tools such as hammers, pliers, picks, universal socket tools, grinders, or bolt cutters. Our convex disc technology prevents your