The ECS-270-20-33-TR: Load capacitance is specified at 20 pF; the 40 Ω ESR is the parameter that most directly governs whether this crystal plays well with your MCU's oscillator circuit — a higher ESR absorbs more drive power and can pull the startup margin on some controllers.
ECX-32 package — T&R and board-fit
Supplied in tape-and-reel (TR) with cut-tape (CT) option, the 4-SMD no-lead package reflow-solders to a standard 3.2 × 2.5 mm land pattern — confirm your layout's pad opening and solder mask clearance match the recommended footprint to avoid tombstoning on the narrow body.