Ars calculates the size of the DualShock 4 touchpad: about 2.1” x 1”

A little image wrangling (and math) generates a general sizing estimate.

DualShock 4 CHU-ZCT2U Touchpad Replacement - iFixit Repair Guide

ISO 9241-9 Evaluation of Video Game Controllers

math Ars Technica

PlayStation Controller Dimensions & Drawings

The PlayStation 4's touchpad and the law of unintended consequences - The Verge

12-inch MacBook month review: A great new Mac if you manage your expectations (Video) - 9to5Mac

February, 2013

eXtremeRate D-pad R1 L1 R2 L2 Trigger Touchpad Action Home Share Options Buttons for ps4 Controller, Chameleon Purple Blue Full Set Buttons Repair Kits for ps4 Slim Pro CUH-ZCT2 Controller

DualShock 4 (CUH-ZCT1U) Touch Pad Replacement - iFixit Repair Guide

Lenovo Tab Extreme Review

Ars Technica

Best Buy: Microsoft Surface Pro 8 – 13” Touch Screen – Intel Evo Platform Core i5 – 8GB Memory – 512GB SSD – Device Only Platinum EBP-00001

DualShock - Wikipedia

Joyonway PB553 Capacitive Touch colour spa touchpad

Almohadilla térmica Hotties para roedores y conejos!, almohadilla térmica

Sterile gauze pads, 4 x 4 in, 100/box.

Always Ultra Thin Overnight Pads with Wings, Size 4, Overnight, 96

Always pad sizes - Size 1 , Size 2 (27 cm), Size 3 (30 cm), Size 4

Always Ultra Thin Size 4 Overnight Pads With Wings Unscented, 52

3M™ Tegaderm™ +Pad Film Dressing, 3584, 2-3/8 in x 4 in, Pad Size